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A fish is vertically below a flying bird...

A fish is vertically below a flying bird moving vertically down toward water surface. The bird will appear to the fish to be

A

moving faster than its speed and also away from the real distance

B

moving faster than its real speed and never than its real distance.

C

moving slower than its real speed and also nearer than its real distance

D

moving slower than its real speed and away from the real distance

Text Solution

Verified by Experts

The correct Answer is:
A
`(mu_(1))/(-u)+(mu_(2))/(v)=(mu_(1)-mu_(2))/(R)`
For a polane surface, `R=oo`
`:. (mu_(1))/(-u)+(mu_(2))/(v)=0`
or `(mu_(2))/(v)=(mu_(1))/(u)` or `(mu)/(v)=(1)/(u)`
`v=muu`
Clearly, to the fish , the bird appears farther than its actual distance.
Again, `(dv)/(dt)=mu(du)/(dt)`
or Apparent speed of bird
`=` refractive index `xx` Actual speed of bird.
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Knowledge Check

  • The fish that swims vertically :-

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    Scoliodon
    B
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    C
    Exocoetus
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